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TRANSCRIPT
NASA Technical Memorandum 104771
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Hypervelocity Impact Testing of theSpace Station Utility DistributionSystem Carrier
Scott Lazaroff
(NASA-TM-I04771) HYPERVELOCITY
IMPACT TESTING OF THE SPACE STATION
UTILITY DISTRIBUTION SYSTEM CARRIER
(NASA) 01 p
N93-30507
Unclas
G3/20 017_968
July 1993
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REVISED ERRATA
NASA Technical Memorandum 104771
Hypervelocity Impact Testing of the Space Station
Utility Distribution System Carrier
by
Scott Lazaroff
Please disregard earlier errata. Replace pages 13, 15, 17, and 27 with the attachedcorrected pages.
NASA Technical Memorandum 104771
Hypervelocity Impact Testing of theSpace Station Utility DistributionSystem Carrier
Scott Lazaroff
Lyndon B. Johnson Space Center
Houston, Texas
National Aeronautics and Space AdministrationLyndon BoJohnson Space CenterHouston, Texas
July 1993
Contents
Section Page
Introduction ................................................................................................................... 1
Test Article Description ................................................................................................. 1Avionic Lines .......................................................................................................... 2Fluid Lines ............................................................................................................. 2
Test Procedure and System Setup .................................................................................. 3Avionic Lines .......................................................................................................... 3Fluid Lines ............................................................................................................. 3
Test Results ................................................................................................................... 3Avionic Lines .......................................................................................................... 4
Secondary Power Lines .............................................................. :. .................. 4
Primary Power Lines ...................................................................................... 5Coaxial Lines .................................................................................................. 51553 Data Bus Lines ...................................................................................... 5
Fiber Optic Lines ............................................................................................ 5Fluid Lines ............................................................................................................. 6
Active Thermal Control System (ATCS) Lines ............................................... 6Environmental Control and Life Support System (ECLSS) Lines .................. 7Supplemental Reboost System (SRS) Lines ................................................... 7
Conclusions and Recommendations .............................................................................. 8Avionic Lines .......................................................................................................... 8Fluid Lines ............................................................................................................. 9
Acknowledgments .......................................................................................................... 10Appendix A: Data for the UDS Avionic Lines Used for HVI Testing .......................... 44Appendix B: Pre-HVI and Post-HVI Avionic Line Functional
Checkout Description .............................................................................. 45Appendix C: List of NASA Photographs from Test Program. ...................................... 50Appendix D: BUMPER-E Vulnerability Analysis of the LIDS Trays ........................... 51
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Figures
Figure Page
1 Typical Section of the Baseline Utility Carrier on the PIT ................................ 112 Typical Cross Sections of the UDS Test Articles ............................................. 123 Typical HVI Setup of Avionic Bundle Test Article and Simulated Carder ........ 12
4 Secondary Power Line Test Setup for a 0 ° Particle Impact (HIRL Shot No.A1493) in the JSC 4.3 mm Light Gas Gun .................................................. 13
5 Active Thermal Control System Fluid Line Test Setup for a 45 ° ParticleImpact (HIRL Shot No. A1614) in the JSC 4.3 mm Light Gas Gun ........... 14
6 Schematic of JSC HIRL Pressure System ........................................................ 157 Bumper and Witness Plate Mounted in 1.7 mm Light Gas Gun Test Cell
from HIRL Shot No. 1941 ...................................................... :. .................. 168 Physical Damage to Secondary Power Lines from HIR Shot No. 1941 ........ 179 Physical Damage to Secondary Power Lines from HIRL Shot No. A1492 ...... 18
10 Physical Damage to Secondary Power Lines from H[RL Shot No. A1494 ...... 1911 Physical Damage to Secondary Power Line Bundle A2A from HIRL Shot
No. A1494 at Magnifications of 10x, 10x, 10x, and 16x ............................. 2012 Physical Damage to Secondary Power Line Bundle A2C from HIRL Shot
No. A1494 at Magnifications of 16x, 16x, 10x, and 10x ............................. 2113 Physical Damage to Primary Power Lines from HIRL Shot No. A1500 .......... 2214 Physical Damage to Primary Power Lines from HIRL Shot No. A1500 at
Magnifications of6x, 10x, and 16x for Line A5B and 10x for ASA ........... 2315 Physical Damage to Coaxial Line Bundle A17B from HIRL Shot No.
A1509 at Magnifications of 6x, 6x, 10x, and 10x ........................................ 2416 Physical Damage to 1553 Data Bus Lines from HIRL Shot No. A1532 .......... 2517 Physical Damage to 1553 Data Bus Lines from HIRL Shot No. A1532 at
Magnifications of 6x and 6x for Line A15A and 6x and 6x forLine A15B ................................................................................................... 26
18 Physical Damage to Fiber Optic Lines from HIRL Shot No. A1539 ............... 2719 Physical Damage to Fiber Optic Line Bundles from HIRL Shot No. A1539
at Magnifications of 6x, 6x, 10x, and 10x ................................................... 2820 Physical Damage to Fiber Optic Line Bundles from HIRL Shot No. A1578
at Magnifications of 6x, 10x, 6x, and 6x ..................................................... 29
21 Bumper, Fiber Optic Bundle and Witness Plate Mounted in 1.7 mm LightGas Gun Test Cell from HIRL Shot No. 2020 ............................................ 30
22 Physical Damage to Fiber Optic Lines from FIIRL Shot No. 2020 .................. 30
23 Physical Damage to Active Thermal Control System Fluid Line from HIRLShot No. A1622 at a Magnification of 10x .................................................. 31
24 Physical Damage to the Internal Wall of the Active Thermal Control SystemFluid Line from HIRL Shot No. A1690 ...................................................... 32
25 Scanning Electron Microscope Photo of the HIRL Shot No. A1688 Tube
Wall, an Impact Crater, and Inner Wall Spalling at a Magnificationof 50x .......................................................................................................... 33
26 Metallurgical Cross Section of Fluid Line from HIRL Shot No. A1688 .......... 3327 Metallurgical Cross Section of Fluid Line from HIRL Shot No. A1690 .......... 34
28 Physical Damage to Environmental Control and Life Support System Linefrom HIRL Shot No. A1631 ........................................................................ 34
29 Physical Damage to Supplemental Reboost System Fluid Line from HIRLShot No. A1751 ........................................................................................... 35
iv
Figure
30
Page
Close-upof Dimple on the Internal Wall of Fluid Line from HIRL Shot No.A1751 .......................................................................................................... 35
Appendix
B 1 Setup for Resistance Check of Secondary Power, Coaxial, and1553 Data Bus Lines ................................................................................... 47
B2 Setup for Resistance Check of Primary Power Lines ....................................... 48B3 Setup for Establishment of Fiber Optic Baseline Conditions ............................ 49B4 Setup for Determining Losses in Fiber Optic Cable ......................................... 49
Tables
Table Page
la Projectile, Target, Bumper, and Wimess Plate Descriptions from JSC HV'ITests of UDS Avionic Lines (Shots 1940, 1941, A1492-A1494, A1498,A1500, A1505, A1507, and A1509) ............................................................. 36
lb Shot Description, Notes/Comments/Damage Descriptions, Avionic Tests, andResults of Avionic Tests from JSC HVI Tests of UDS Avionic Lines
(Shots 1940, 1941, A1492-A1494, A1498, A1500, A1505, A1507,and A1509) .................................................................................................. 37
2a Projectile, Target, Bumper, and Witness Plate Descriptions from JSC HVITests of UDS Avionic Lines (Shots A1517, A1526, A1532, 2020, A1539,A1543, A1576, and A1578) ....................................................................... 38
2b Shot Description, Notes/Comments/Damage Description, Avionic Tests, andResults of Avionic Tests from JSC HVI Tests of UDS Avionic Lines
(Shots A1517, A1526, A1532, 2020, A1539, A1543, A1576,and A1578) .................................................................................................. 39
3a Projectile, Target, Shot, and Bumper Descriptions from JSC FrvI Tests ofUDS Fluid Lines (Shots A1613, A1614, A1622, A1626, A1631, A1640,A1651, A1688, and A1690) ......................................................................... 40
3b Witness Plate Description, Bumper Damage, Damage Description of WitnessPlate, and Notes/Comments/Damage Description from JSC HVI Tests ofUDS Fluid Lines (Shots A1613, A1614, A1622, A1626, A1631, A1640,A1651, A1688, and A1690) ......................................................................... 41
4a Projectile, Target, Shot, and Bumper Descriptions from JSC HVI Tests ofUDS Fluid Lines (Shots A1693, A1695, A1749-A1751, and A1800) ......... 42
4b Wimess Plate Description, Bumper Damage, Damage Description of WitnessPlate, and Notes/Comments/Damage Description from JSC HVI Tests ofLIDS Fluid Lines (Shots A1693, A1695, A1749-A1751, and A1800) ......... 43
Appendix
D1 LIDS Tray Dimensions ..................................................................................... 52D2 Results of Analysis ........................................................................................... 53
V
Acronyms and Abbreviations
AIATCSAWG
cin
dB
ECLSS
FEP
GN2
HALHIRLHVI
in.
JSC
kmkm/skPa
LEO
MDA-t'IB
M/OD
_nmAi3m-n
MPa
NASA
OD
PFAHTPTFE
SEMSRSSSF
t
UDS
WSTF
aluminum
Active Thermal Control SystemAmerican wire gage
centimeter
decibel
Environmental Control and Life Support System
fluorinated ethylene propylene
gaseous nitrogen
Hypervelocity Analysis LaboratoryHypervelocity Impact Research Laboratoryhypervelocity impact
inches
Johnson Space Center
kilometer
kilometer per secondkilopascal
low Earth orbit
McDonnell Douglas Aerospace-Huntington Beachmeteoroid and orbital debrismicrometer
milliampmillimeter
megapascal
National Aeronautics and Space Administration
outer diameter
pcrfluoralkoxypre-integrated tresspolytetrafluorethylene
Scanning Electron MicroscopeSupplemental Reboost SystemSpace Station Freedom
thickness
Utility Distribution System
White Sands Test Facility
vi
Abstract
The Utility Distribution System (UDS) of the Space Station Freedom (SSF) is, inpart, responsible for routing avionic and fluid utilities along the pre-integrated trusssegments. These lines arc housed in a rectangular aluminum carrier that providesprotection from the impacts of meteoroid and orbital debris (M/OD) particles. An initialanalysis completed by McDonnell Douglas Aerospace-Huntington Beach estimated thatthe avionic lines in the UDS carrier could experience approximately 200 failures per year.This number is based on a very conservative failure criteria that any penetration into theavionic portion of the UDS carrier would cause an avionic line to fail. This conservativecriteria had to be used because little is known about the effects of M/OD on avionic and
fluid lines, especially behind a protective carrier cover. As a result, a two-phase jointNASA Johnson Space Center and McDonnell Douglas Aerospace-Huntington Beachhypervelocity impact (I-IV'I) test program was initiated to develop an improvedunderstanding of how M/OD impacts affect the SSF avionic and fluid lines routed in theUDS carrier.
This report documents the first phase of the test program which covers nonpoweredavionic line segment and pressurized fluid line segment HVI testing. From these tests, abetter estimation of avionic line failures is approximately 15 failures per year and couldvery well drop to around I or 2 avionic line failures per year (depending upon the resultsof the second phase testing of the powered avionic line testing at White Sands). For thefluid lines, the initial McDonnell Douglas analysis calculated 1 to 2 line failures over a 30year period. The data obtained from these tests indicate the number of predicted fluidline failures increased slightly to as many as 3 in the first 10 years and up to 15 for theentire 30 year life of SSF.
vii
Introduction
Since the Space Station Freedom (SSF) will be exposed to a low Earth orbit (LEO)
environment (up to a 500-km altitude), it must be designed to withstand both meteoroid andorbital debris (M/OD) collisions. Specifically, the Utility Distribution System (UDS) is
required to provide M/OD protection for its fluid and avionic lines to a level that, whenconsidering redundancy and repair capability, provides an acceptable system. Yet, littleinformation exists on how M/OD impacts affect pressurized fluid and avionic lines behind aprotective bumper.
For the UDS, the protective bumper is the utility carrier--a rectangular box that runs the
length of the Space Station and made of 0.64 mm (0.025 in.) thick 7075-T73 aluminum(A1). There are two primary carriers where utility lines are routed, one on face 2 and one onface 6 of the hexagonal pre-integrated truss (P1T) segments.
One way of estimating the level of M/OD impacts or failures for a particular design isto use penetration equations that have been derived from empirical data of previoushypervelocity impact (HVI) tests. These equations, such as the Cour-Palais orFish/Summers penetration equations, provide an analytical method to make theseestimations. A study performed by McDonnell Douglas Aerospace-Huntington Beach(MDA-HB) in July of 1991 calculated the number of failures that can be expected of theUDS fluid and avionic lines inside the carders (reference MDA-HB report no. MDC91-H0643, section 4.5.3). The results showed 5650 avionic line failures and 1 to 2 fluid line
failures over a 30 year period (or approximately 200 failures/year). It is important to notethat a very conservative failure criteria assumption was used for the avionic lines becauseof the lack of available data regarding M/OD impacts on utility lines. The assumptionused was that any penetration through the carrier would cause an avionic line failure.
To better understand M/OD impacts and the affect they have on the avionic and fluidlines in the LIDS carder, an HVI test program was initiated. This coordinated test programbeing performed by the Johnson Space Center (JSC) and MDA-HB is separated into twophases. The fast phase of tests, under the direction of the Power Branch of the Propulsionand Power Division, is with segments of inactive avionic lines and pressurized fluid utilitylines behind a simulated UDS carder cover. The second phase uses active avionic lines andpressurized fluid lines (with longer lengths of lines and representative fluid systemvolumes). These tests in the second phase will be conducted with the articles behind both asimulated LIDS carder and housed in a flight-like UDS carrier.
The testing described in this report covers the HVIs completed on the inactive UDSavionics lines and pressurized fluid lines (phase 1), at the JSC Hypervelocity ImpactResearch Laboratory (HIRL), from January through May of 1992 and September throughOctober of 1992, respectively. Its primary objective was to perform an engineeringcharacterization of the damage tolerance of the UDS lines inside the carders. Thisinformation will feed directly into building the test matrix for the next phase of the avionicand fluid line tests that is to be conducted at White Sands Test Facility (WSTF). A
secondary objective was to investigate the effects of the HVIs on functional characteristicsof the avionic lines. Also, a more realistic number of failures of UDS lines inside the carrier
will be estimated using the test data and a probability analysis computed by the BUMPER-E M/OD modeling code.
Test Article Description
The test articles used are representative of the LIDS avionics and fluid lines which areenclosed inside the carrier in individual sections separated by a thin metal barrier. Figure 1shows a typical portion of the current baseline configuration of the utility carders on thePIT.
Avionic Lines
The types of avionic lines tested were secondary power, primary power, coaxial, 1553data bus, and fiber optic lines. Except for the primary power line tests, the test articles for
each HVI were usually two bundles, each consisting of 7 lines that were approximately 30.5- 35.6 cm (12 - 14 in.) long with minimal spacing between the bundles. The goal here wasto provide adequate target area for an accurate shot and enough length of line to capture asmuch debris as possible. Because interest was being focused on the lines of the bundle thatwere struck first by the particle/debris, a lot of excess lines in the bundle were notnecessary.
The primary power lines had a large enough diameter that bundling was not required,so, two or three individual lines provided a sufficient target area. Figure 2 shows the typicalcross sections of the UDS test articles that were used for the HVIs. Some specificationsfor the avionic lines are given in appendix A.
The test articles were placed approximately 8.5 cm (3.35 in.) behind a 15.2 x 15.2 cm(6 x 6 in.) piece of 0.64 mm (0.025 in.) thick 7075-T73 A1 bumper that represented theUDS carrier cover. In an M/OD protection system, the bumper is a single sheet of materialthat is used to break up the incoming particle. This dissipates the particle's energy andmakes the resulting debris cloud less potent. A constant distance of 8.5 cm was usedbecause it represented the worst case (shortest) spacing between the avionic lines and thebumper. According to MDA-HB drawing no. 1F02896 (August 1991), the distancebetween the UDS carder cover and the largest bundle had been approximated at 8.5 cm.Furthermore, the size of the bundles could vary and this dimension had not been determinedfor the actual bundles in the Space Station carder.
In addition, a witness plate of 0.64 mm thick 7075-T'/3 A1 was placed typically 20.3 cm(8.0 in.) behind the bumper (approximately 11.4 cm or 4.5 in. behind the test articles). Thisdistance corresponds to the depth of the actual Space Station carrier. Information on thedimensions of materials and spacing used for all the avionic tests are also given in tables laand 2a.
An example of the typical layout of the avionic test articles and the simulated UDS
carrier in the test cell, for a shot with an impact angle of 0 ° (relative to the projectile's path),is illustrated in figure 3. A photograph of an actual secondary power line test setup, in theJSC HIRL 4.3 mm light gas gun, is shown in figure 4.
Fluid Lines
The tubing used for the fluid line test articles represented the SSF Active ThermalControl System (ATCS), Environmental Control and Life Support System ('ECLSS), andthe Supplemental Reboost System (SRS). All the tubing was 304L stainless steel and hadthe following outer diameters (OD) and wall thicknesses:
ATCS:ECLSS:SRS:
4.45 cm OD x 0.089 cm wall (1.75 in. OD x 0.035 in. wall); welded1.27 cm OD x 0.051 cm wall (0.50 in. OD x 0.020 in. wall); seamless0.95 cm OD x 0.089 cm wall (0.375 in. OD x 0.035 in. wall); seamless
The tubes were cut to about 36 cm (14 in.) lengths and the ends were flared to
accommodate 37 ° military standard fittings. These end fittings were used to adapt the testarticles to the 1/4 in. tubing required by the JSC HIRL pressure system. For the largediameter ATCS lines, special reducers had to be constructed by welding a 1/4 in. union to a1.75 in. plug and drilling a hole through the assembly. These special plugs and the rest ofthe fluid test article preparations were fabricated at the JSC Thermochernical Test Area.
The spacing between the fluid test articles and the bumper varied depending upon thesize of the fluid line being shot. These distances were based on the spacing of the carrier
2
barfrom thecarrier cover shown in MDA-HB drawing no. 1F02896 and are given in tables3a, 3b, 4a, and 4b. The bumper and wimess plate material (0.64 mm thick 7075-T73 A1)and dimensional specifications used are the same as in the avionic line tests. The witness
plate was placed 20.3 cm behind the bumper.A photograph of one of the ATCS fluid line HVI test setups, at an impact angle of 45 °
(relative to the path of the projectile), is shown in figure 5.
Test Procedure and System Setup
Avionic Lines
Each avionic HVI test consisted of four parts: a pre-HVI functional check, the HVI
shot, a post-HVI functional check, and the visual inspection/physical damagedocumentation. The functional checks were performed to determine the current carryingcapability of the lines before and after the H'VI tests. This consisted of light signaldegradation measurements for the fiber optic lines, or resistance and dielectric breakdown(current leakage) measurements for the other types of avionic lines. A more detaileddescription of these functional checks is given in appendix B. Two of the three HIRL lightgas guns, the 1.7 mm and the 4.3 mm guns, were used for this portion of the testing. Foreach shot, the test article was installed at the required impact angle and the target chamberevacuated. The vacuum level in the chamber depended upon which light gas gun was used.The smaller, 1.7 mm (0.07 caliber) gun uses aerodynamic sabot separation, and it was
evacuated to approximately 9.5 - 10 torr (about 0.2 psia). The 4.3 mm (0.17 caliber) gunhas a rifled barrel and was pumped down to a vacuum level, approximately 0.5 - 2.0 tort
(0.01 - 0.04 psia), for the shot. After the shot, the test articles were photographed,examined, and sent through the post-test functional checks. All HVI shots, test parameters,and results of the inspections are discussed in the Test Results section.
Fluid Lines
The testing for each type of tubing was composed of two parts: 1) fluid lines atambient pressure and 2) fluid lines at maximum on-orbit system pressure. The test articlewas installed in the target chamber of the 4.3 mm light gas gun at the specified impact angle
(figure 5), and the target chamber was evacuated to approximately 0.5 - 2.0 torr (0.01 - 0.04psia). All of the fluid line tests were performed with the 4.3 mm gun. The test article wasthen pressurized and the light gas gun was fired. A schematic of the JSC HIRL pressuresystem is shown in figure 6. After the shot, a visual inspection was made to document thedamage on the lines. This included examinations with a borescope, a Scanning ElectronMicroscope (SEM), and a metallograph. These findings are described in the Test Resultssection.
Test Results
The main objective of this test program was to gather data on the physical damage tothe UDS carrier utility lines sustained from simulated M/OD HVIs. Also, the effects theseparticles have on the functional characteristics of the avionic lines were examined. Theinformation obtained during the HVI tests and post-shot functional examinations is used toestablish a ballistic limit of the utility lines that are protected by the UDS carrier. This leadsto a better estimation of the number of avionic and fluid line failures to be expected and a
better estimation of whether the current UDS M/OD protection design is adequate.
Theterm ballistic limit is used to describe the conditions that cause a failure in a
particular shield system. For this test program, the shield system consisted of the protectivebumper (carrier cover) and the rearwall (fluid or avionic line test articles). A ballistic limit isdefined by the parameters of the particle impact such as particle velocity, particle size andmaterial, impact angle, and the type of fluid or avionic line test article. For example, theinitial shot at a shield system uses a certain size particle at a set velocity. The particle size isincreased (or decreased) until the smallest particle which causes the shield system to fail isfound. At that point, a ballistic limit for that system, particle, and velocity has beendetermined, but for these parameters only. If any one of these variables is changed, thentesting must be performed to determine a new ballistic limit.
For this HVI testing, the basic emphasis was to determine what size particle, traveling atapproximately 6.5 km/s and hitting the bumper at 0 ° or 45 °, would cause a failure of the
avionic and fluid lines in the UDS carrier. In other words, the goal was to establish theballistic limit of the UDS lines in the carrier for particles striking the cover at 6.5 km/s at an
impact angle of 0 ° or 45 °. This data was then directly used by the BUMPER-E impactanalysis tool to get a better determination of the effectiveness of the UDS carrier to protectthe lines from M/OD (see Conclusions and Recommendations).
A detailed description of the test articles, the shots, and the physical and functionalcheckout results can be referenced in tables la, lb, 2a, and 2b for the avionic lines and tables
3a, 3b, 4a, and 4b for the fluid lines. A listing of all photographs taken during this testprogram is given in appendix C.
An important note for this testing is that there are a number of shots where a piece ofdebris (either from the pump tube piston or a piece of sabot that was shed from around the
particle) trailed the particle through the light gas gun and impacted the bumper plate. Basedon the visual evidence left by the debris and the expertise of the members of the HIRL, thisdebris did not affect the damage on the test articles that were sustained from the actual HVIparticle. Where there was a question regarding the significance of the debris on the testarticle damage, a repeat shot was performed.
Avionic Lines
A set of criteria was established for these HVI tests to determine the extent of
functional damage the lines would have to receive to classify them as failed. This failurecriteria was put together with the help of SSF engineers responsible for the particular typeof avionic lines used in these tests. For the power, data bus, and coaxial lines, the failurecriteria was > 5 mA of current leakage and/or a 10 - 15% increase in resistance. For thefiber optic lines, a signal loss of 8 - 10 dB constituted a failed line.
Secondary Power Lines
The first set of HVI shots conducted for this test program used secondary power linesas the test articles. Because little was known of the effects of M/OD on avionic lines, theinitial shots were conservative using very small particle sizes. Figure 7 shows the bumperand witness plate mounted in the test setup from HIRL shot no. 1941 (post-HYI and withtest articles removed). Figure 8 is a close-up picture of these test articles from HIRL shot
no. 1941. This shot used a 0.8 mm (1/32 in.) diameter A1 sphere traveling 6.66 km/s. Theparticle penetrated the simulated carrier cover, but did very little physical damage and did notdegrade the insulation or increase the resistance of the lines. This is very important becausethe MDA-HB estimation described earlier used a failure assumption that any penetrationthrough the carrier would cause an avionic line failure. These tests prove that even thoughthe particle penetrates the bumper (simulated carrier cover) a failure does not necessarilyresult. HIRL shot no. A1492 is another example of the particle perforating the bumper, yetcausing no functional deterioration in the lines (figure 9 and tables la and lb).
A preciseballisticlimit wasnotdeterminedfor secondarypowerlines. A 2.4mm (3/32in.) diameterA1spherestrikingthesimulatedcarriercoverat45° (HIRL shot no. A1494)was the biggest particle fired at the secondary power lines. It caused a large amount ofphysical damage (figures 10, 11, and 12), and a few of the test article lines indicated someslight increases in resistance during the post-HV checkout. There was no dielectricbreakdown of the insulation on any of the secondary power lines. For this part of the HVItest program, the parameters of A1494 are on the borderline of the ballistic limit curve, andthe WSTF active line testing will better establish this limit.
Primary Power Lines
For the primary power lines, an exact ballistic limit was not identified. The HVI of a3.2 mm (1/8 in.) diameter A1 sphere striking the bumper at 45 ° (HIRL shot no. A1500)
caused significant insulation damage and severed a small number of conductor strands(figures 13 and 14). However, there was no increase in resistance. Dielectric breakdown(current leakage) of the lines was not tested.
Coaxial Lines
The ballistic limit for the coaxial lines is estimated to be near the parameters of HJRLshot no. A1509. For this shot, a 2.4 mm diameter A1 sphere striking the bumper at 45 ° was
used, and it damaged one line enough to expose the inner conductor (figure 15). This linedid not increase in its resistance reading, but it did have > 5mA of current leakage from theinner conductor to the outer shield. This is enough loss in insulation protection to cause afunctional failure of that line (appendix B).
1553 Data Bus Lines
HIRL shot no. A1532 used a 2.4 mm diameter A1 sphere striking at 45 ° and caused
significant dielectric breakdown (> 5mA of current leakage = failure assumption) in severallines of both test article bundles. The physical damage to the data bus lines from this shotis depicted in figures 16 and 17. The results of this test indicate that the parameters are wellwithin the ballistic limit since many lines failed. A smaller particle was not shot at theselines, but it will be included as part of the recommendations for the active avionic HVI testsat WSTF.
Fiber Optic Lines
The ballistic limit for the fiber optic lines is found from the HIRL shot no. A1539, inwhich a 1.6 mm diameter A1 sphere impacted the bumper at 45 °. The signal losses in thetwo severely damaged fiber optic lines of shot A1539 were 35.4 and 36.3 dB. Based on thefailure criteria, this is significant enough for a functional failure of the line. The physicalline degradation associated with shot A1539 can be seen in figures 18 and 19.
The ballistic limit conclusion is reached because a repeat of the A1539 parameters wasmade (HIRL shot no. A1578), and the post-HVI check showed no loss of light signal
through the line. As seen in figure 20, the physical damage is very similar to the damage tothe fines from HIRL shot A1539. Thus in a worst case, the parameters of A1539 andA1578 can cause a failure in the fiber optic lines and therefore they lie on the border of theballistic limit curve.
In addition, figures 21 and 22 indicate similar findings described in the secondarypower lines summary of results. It can be seen that small particles (< 1.6 mm in diameter)penetrate the bumper, yet cause little physical damage and no functional damage.
5
Fluid Lines
The failure criteria for this testing must be mentioned before interpreting the results indetail. This criteria is that only a perforation of the test article tube wall is specifically
called a failure and not a specified degree of spall or depth of an impact crater. These lattertwo phenomena may have some affect on the strength of the line so that the burst pressurerating of the line is reduced, but for this testing these damage phenomena will not classifythe test article as a failed line.
Active Thermal Control System (ATCS) Lines
Several shots were performed with the test articles filled with water and pressurized to101 kPa (14.7 psia) to simulate liquid anamonia filled lines. The most significant resultswere obtained from HIRL shot nos. A1622 and A1688. Under the failure criteria stated
previously, the ballistic limit parameters found for this testing come from HIRL shot no.
A1622. It had a 2.4 mm diameter A1 sphere striking the bumper at 45 ° and approximately6.5 km/s. The failure criteria for the fluid line tests is a perforation of the tube wall, and thisparticle caused two perforations, 0.85 x 1.8 mm and 1.52 x 1.52 mm (figure 23). The testarticle from HIRL shot no. A1688 used a 2.0 mm diameter particle, striking the bumper at45 ° and about 6.8 km/s. It sustained some serious crater damage which caused dimpling ofthe internal wall, but no perforation resulted.
HIRL shot no. A1690 was performed with nearly the same parameters as A1688,except that the water in the line was pressurized to the maximum ATCS pressure of- 2.0MPa (286 psia). This fluid line had serious crater damage which also caused some internaldimpling, but again, no perforation of the wall occtmed.
Further structural analyses were performed on the fluid line test articles from shots
A1688 and A1690 at the JSC Structures and Mechanics Division Laboratory. Initially, aborescope was used to get a better picture of the internal dimples. Upon identifying somepotential detached spaU, a series of x-rays was taken to document the tube damage and todetermine if any changes in material density had occurred. These radiography pictures wereinconclusive.
Next, the lines were cut longitudinally and the internal damage photographed. Figure24 shows a "rift" in a dimple from the inside wall of the HIRL shot no. A1690 test article.
The most heavily damaged area of the lines was subsequently cut from the tubes and theexternal craters and internal dimples documented using a JEOL JSM-820 SEM. The pieceswere then sectioned through the crater location and further documented with the SEM. TheSEM examination identified the spalling of the internal tube wall surface, showed the
interface between the particle debris and the fluid line, and noted the compression of thegrain structure at the point of impact. Figure 25 is an example of a typical SEM photoshowing a cross-sectional view of the tube wall from HIRL shot no. A1688, a crater, and theresultant spalling of the inner wall.
In addition, a cross section of the impact area was looked at using a Zeiss AX10MATmetallograph. These metallurgical cross sections further clarified the degree of spaUing ofthe internal fluid line wall. As can be seen in figures 26 and 27, there is significant damageto the test article from HIRL shot nos. A1688 and A1690, respectively.
HIRL shot nos. A1688 and A1690 had some debris from the pump tube piston impactthe bumper. This debris may have done some damage to the test articles. The parametersof HIRL shot A1690 were repeated in HIRL shot no. A1800 to make certain the unwanted
piston did not cause the damage discussed above. Since A1688 and A1690 used verysimilar shot parameters, both were not repeated. A1800 was a clean shot and initialinspection showed several dimples on the internal wall of the test article. The fluid line was
cut open and these dimples closely compared to the ones found in A1688 and A1690.Therefore, k is concluded (without the need for further destructive analyses) that the damage
6
to thetestarticlesfrom shotsA1688andA1690wasindeedcaused by the particle and not
some foreign debris.Based on the criteria that a perforation of the tube wall constitutes a failure, the
parameters of HIRL shot no. A1622 are obviously beyond the ballistic limit of these fluidlines. However, the analyses of the test article from shots A1688 and A1690 clearly show
major structural damage to the tube wall at that impact point. This results in a weak spot inthe line, and may be a concern if a pressure surge were to occur. Nonetheless, it can beconcluded that the parameters of HIRL shot nos. A1688 and A1690 are barely below, if not
right at, the ballistic limit for these ATCS lines.Also, HIRL shot nos. A1688 and A1690 were conducted with almost identical
parameters except for water pressure. It was determined that the higher internal storedenergy of the test article from A1690 did not significantly affect the damage caused duringthe HVI. The maximum internal system pressure of approximately 2.0 MPa (286 psia)stresses this line less than 20% of its yield strength. The slightly deeper craters and visibleinternal wall damage on A1690 are more likely due to the lower impact velocity rather than
the higher internal pressure.
Environmental Control and Life Support System (ECLSS) Lines
These lines simulated a 1.4 MPa (200 psia) gaseous nitrogen (GN2) ECLSS line thatwill be used to pressurize the SSF external ATCS tanks and pump module hardware. Thefirst three shots were performed with the test articles at this SSF system pressure (1.4MPa), and the results indicate that the ballistic limit is near the parameters of HIRL shot no.A1631. In this shot, a 2.0 mm diameter particle impacted the bumper at 45 °, and thesubsequent cloud of debris created a 0.8 x 0.8 mm and a 1.0 x 1.1 mm perforation in the
tube wall (figure 28). HIRL shot no. A1640 used a slightly smaller particle size of 1.8 mmat the exact same parameters and only caused some mamng and craters on the externalsurface of the tube.
Next, the 1.8 and 2.0 mm particles were shot at lines also pressurized with GN2, butonly to 101 kPa. The test articles of HIRL shot nos. A1693 (using a 2.0 mm particle) andA1695 (using a 1.8 mm particle) both sustained perforations of the tube wall. Shot A1693resulted in a hole in the tube approximately 0.6 x 0.7 ram. The penetration in the line fromA1695 is 1.1 x 1.6 mm and though it is believed to have been caused by the actual testparticle striking the bumper, it could have originated from the piece of debris that followedthe particle. This debris impacted the bumper very close to where the test particle did, so itis difficdt to determine which may have caused the tube wall perforation. As a result, theparameters of shot A1695 were repeated in HIRL shot no. A1749 and no perforation of thetest article resulted. However, two visible dimples on the internal surface were found and onfurther examination, one of the dimples had detached spall. Therefore, it is determined thatthe parameters of HIRL shot no. A1693 are just past the ballistic limit for these ECLSSlines, while A1749 (and A1695) is right on the limit.
Supplemental Reboost System (SRS) Lines
Two shots were conducted with lines that represented the SSF SRS lines. The SSFSRS will collect, store, and propulsively dispose of waste gases. For these tests, the lines
were pressurized with GN2 to the maximum SRS pressure of 6.9 MPa (1000 psia). Noperforations of the tube wall were produced in these two tests, but the test article from HIRLshot no. A1751 did sustain some significant damage (figure 29). There are two particularlylarge and deep craters that penetrate approximately 0.30 - 0.35 mm into the wall and causethe internal surface of the tube to dimple. These dimples were observed with the borescope,and it appeared that one could have some possible detached spall.
A structural analysis on the line from shot A1751, similar to the one completed on theATCS lines, was completed and documented. Figure 30 definitely indicates some detached
7
spallon thefightinternaldimple and thestartingof some detached spallon theother(small
crack/flakingofmaterial).Furtherobservationunder thestereoscopicmicroscopesubstantiated the spaUing that occun'ed on the internal surface of the tube. As a result, it isconcluded that the parameters from HIRL shot A1751 lie on the borderline of the ballisticlimit for these lines.
A slower moving piece of debris (relative to the particle) penetrated the bumperapproximately 1.5 cm down and 1.1 cm to the right of the particle impact point. It is similarto the type of debris seen in the ATCS tests. Because of its speed and location and for thereasons discussed earlier for the ATCS lines, it is concluded that the particle and not thedebris produced the serious damage to the SRS line described here in the results.
Conclusions and Recommendations
The overall goal of this phase of the HVI test program was to develop an improvedunderstanding of how M/OD impacts affect the SSF avionic and fluid lines routed in theUDS carrier. The need for the program arose from the results of some initial and veryconservative analyses which predicted up to 200 failures per year could occur in these UDSlines. This report documents that the program goal was achieved with great success.Specifically, the three objectives of 1) perfomaing an engineering characterization of the
damage tolerance of the UDS avionic and fluid lines inside the carrier, 2) investigating theeffects of the simulated M/OD impacts on the functional characteristics of the avionic lines,and 3) estimating a more realistic number of failures of UDS lines inside the utility carriers,were sufficiently met. This phase of testing filled a void where little data had previouslyexisted. The information will help demonstrate how good the baseline UDS carrier designis from an M/OD protection standpoint and will feed directly into determining how muchextravehicular activity maintenance time is required to replace functionally damaged/failedUDS lines on SSF. A synopsis of the conclusions reached during the testing is givenbelow.
Avionic Lines
First, the JSC HVI tests prove that the conservative assumption used in the initialMDA-HB analysis is not true. This assumption stated that any penetration through thecarrier would cause an avionic line failure. Several tests on the secondary power and fiberoptic lines show that particles less than 1.6 mm in diameter (which constitute a majority ofthe particle sizes in the LEO environment) do penetrate the simulated UDS utility carriercover, but only do minimal physical damage and do not degrade the insulation or increasethe resistance of the lines.
In addition, some of the physical damage on the avionic lines seemed severe from a
visual standpoint. Insulation was destroyed and often conductors exposed. However, theselines passed the avionic line functional checks, indicating the cabling would work properly.Therefore, they were not considered failures.
These conclusions are made with the understanding that the HVI testing of poweredavionic lines at WSTF will add some crucial data that could alter the answers found here.
At the completion of these JSC HVI tests, a vulnerability analysis was performed bythe JSC Hypervelocity Analysis Laboratory (HAL) using the BUMPER-E computer model.It predicted the expected number of impacts on the avionics and fluid sections of the LIDS
carrier for several test particle diameters. A more detailed description of the BUMPERanalysis is shown in appendix D. Based on the data obtained from the HVI tests and this
BUMPER nan (which used an updated environment model and penetration equationcompared to the original MDA-HB analysis), a better estimation of the number of failuresto the avionic lines was determined. Instead of anticipating up to 200 avionic line failures
peryear,approximately 15 failures per year was found to be more realistic. This numberis still conservative and could potentially drop to around I or 2 avionic line failures per
year. However, the final determination of the number of avionic line failures will depend
upon the outcome of the powered avionic line HVI testing at WSTF.An additional conclusion reached from the BUMPER-E computer run was that the
upper LIDS carrier will be hit by more M/OD than the lower carder. This is due to the typeof attitude that the SSF will by flying in LEO. The ratio of impacts on the upper carrier to
the impacts on the lower carrier are as great as 10 to 1 when the Space Shuttle Orbiter isdocked to SSF. When the Orbiter is not docked, the ratio decreases to about 1.7 to 1.
The data gathered in this testing at JSC also provided a lot of background informationfor this next phase of tests at WSTF. The following are some recommendations on particlesizes that could be used during those active line tests.
Secondary_ Power Lines: The initial shot should be with a 2.4 mm or even a 1.6 mmdiameter A1 sphere striking at 45 °. These lines will operate at 120 volts, and under full loadconditions they will carry 58 A. Because of the potential of a high current fault, the smallerparticle is suggested.
primary Power Lines: A shot with a 2.4 mm diameter A1 sphere striking at 45 °should be used as a starting point for a similar reason as described above for the powered
secondary power lines.i_,9.11V_..ldll_: A shot with a 1.6 mm diameter A1 sphere striking at 45 ° is suggested
to be used as a starting point during the active avionic HVI tests at WSTF.1553 Data Bus Lines: It is recommended that the initial shot should be with a 1.6 mm
diameter A1 sphere striking at 45 °. This is because several lines were found to befunctionally damaged with a 2.4 mm diameter particle striking the bumper (HIRL shot no.A1532). A smaller particle might have enough kinetic energy to cause functional damage toa single 1553 data bus line. Thus, the parameters of A1532 could be past the ballistic limit.
Fiber Optic Lines: It is recommended that a shot with either a 1.6 mm or slightlysmaller particle (such as a 1 ram) diameter A1 sphere striking at 45 ° should be used as astarting point.
Fluid Lines
An issue with the fluid line tests was whether the internal pressure of the SSF systemswould add to the hazard of an M/OD impact. This extra potential energy in the test articles
was investigated and found not to be significant for the lines on the Space Station. First, thehoop stress calculated for the fluid lines used in the I-IVI testing was only 15% to 20%(maximum) of the yield stress of 304L stainless steel. Second, tests conducted on theATCS and ECL_S lines at system and ambient pressures showed little variance in the
degree of damage experienced. For example, the test articles from I-IIRL shot nos. A1688and A1690 had very similar amounts of damage on the external and internal wall surface.
Another conclusion was that the initial estimate of I to 2 fluid line failures over the 30
year life of the Space Station is slightly low. Based on the distribution of particlescalculated by the BUMPER-E run discussed above and the data from the HVI tests, asmany as 3 fluid line failures could be experienced in the first 10 years and overall up to 15for the entire 30 year life of SSF. At the conclusion of the WSTF testing and a moredetailed BUMPER-E UDS carder analysis, a better calculation will be provided.
For the WSTF fluid lines, some slight variations on wall thickness will be used basedon additional design information during the planning for phase 2. The data obtained from
phase 1 at JSC will help. pick the appropriate shot parameters for phase 2, but norecommendations are gaven at this time.
9
Acknowledgments
Thanks are extended to all the personnel at the JSC HIRL and HAL who conducted the
HVI shots, helped set up the test system, assisted in post-test visual inspection/dataanalyses, and completed the BUMPER-E computer modeling of the lADS carriers. Theyinclude Jeanne Crews, Manager of the HIRL, and Eric Christiansen, Manager of the HAL(both of the Space Science Branch at JSC). Also included are Pat White, Joe Falcon, JayLaughman, Earl Brownfield, and Lu Borrego (Lockheed support contractors at the HIRL),and Javier Ortega, Jim Hyde, and Gillian Shephard (Lockheed support contractors at theHAL).
Bill Holton, Lockheed support at the Electrical Power Systems (EPS) Laboratory,assembled all the avionic test article cable bundles and performed the pre-HVI and post-HVI checkouts on the power, coaxial, and 1553 data bus lines.
Rick Dean of the JSC Thermochemical Test Area fabricated all the fluid line testarticles.
Glenn Morgan, Lockheed support of the 3SC Structures and Mechanigs Division,performed the SEM and metallograph analyses of the specific fluid lines discussed in theresults.
10
Carrier Covers (bumper)
Fluid Line Section Avionic Line Section
Hgurc 1. Typical Section of the Baseline Utility Carrier on the PIT
11
Secondary Power, Coaxial,and 1553 Data Bus Bundles
BundleDiameter
Individual
Lines __
Fiber Optic Bundles
Primary Power Lines
Figure 2. Typical Cross Sections of the UDS Test Articles (not to scale)
Sabot Catcher
UDS lines mounted
to cut-out plate Witness Plate
Particle Path
iParticle
Figure 3. Typical HVI Setup of Avionic Bundle Test Article and Simulated Carrier
12
Figure 4. Secondary Power Line Test Setup for a 0 ° Particle Impact (HIRL Shot No.A1493) in the JSC 4.3 mm Light Gas Gun.
o_G_, L pp,G_I_ D '¢,1__'x_ p_o._O_P_
13
Figure5. ActiveThermalControlSystemFluid LineTestSetupfor a45° ParticleImpact(HIRL ShotNo. A1614)in theJSC4.3mm Light GasGun
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17
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Figure 9. Physical Damage to Secondary Power Lines from HIRL Shot No, A1492
ORIGIN/_ PAGE
BLACK AND WHITE PHOTOGRAPH
18
Figure 10. Physical Damage to Secondary Power Lines from HIRL Shot No. A1494
19
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Figure 22. Physical Damage to Fiber Optic Lines from HIRL Shot No. 2020
30
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Figure 25. Scanning Electron Microscope Photo of the HIRL Shot No. A1688 TubeWall,an Impact Crater, and Inner Wall Spalling at a Magnification of 50x
Figure 26. Metallurgical Cross Section of Fluid Line from HIRL Shot No. A1688
33
Figure27. MetallurgicalCrossSectionof Fluid Linefrom HIRL ShotNo.A1690
Figure28. PhysicalDamageto EnvironmentalControlandLife SupportSystemLinefrom HIRL ShotNo. A1631
34
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wall dimples shownin figu_ 30
Figure 29. Physical Damage to Supplemental Reboost System Fluid Line from HIRLShot No. A1751
Figure 30. Close-upofDimple on thelntemalWallofFluid Line _omHIRLShotNo.A1751
35 ORIGINAl: P-A-G_
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43
APPENDIX A: DATA FOR THE UDS AVIONIC LINES USED FOR HVI TESTING
1553 Data Bus Cable (MIL-C-17F. M17/176-00002_
Twisted, shielded pair
Inner conductors:
Outer conductor:
Jacket:
Two 24 American wire gage (AWG) consisting of 19strands of 36 AWG silver-coated, high strength copper alloySingle braid of 38 AWG silver-coated, high strengthcopper alloy wirePFA; Diameter 0.129 + 0.005 in.
Primary_ Power
1/0 AWG line conductor
Cable diameter:Conductor:Insulation:
0.545 + 0.010 in.
Class N, nickel-coated, stranded copper rope laySilicone
Secondary Power
Twisted pair, unshielded and unjacketed
Cable diameter: 0.150 in.
Conductors: 18-gage stranded conductorsInsulation: Teflon
Coaxial Cable (RG-142Bfl, I)
Inner conductor:Dielectric core:
Outer conductor:Jacket:
Solid silver-coated, copper-covered steel wireSolid extruded PTFE (inner conductor insulation)Double braid of 36 AWG silver-coated copper wireTeflon FEP; Diameter 0.195 + 0.005 in.
Fiber Ootic Cable
100/140 gtm type (core =
Cable diameter:
Optical fiber:Protective coating:Tube:
Strength member:Jacket:
100 gtm, cladding = 140 grn)
0.083 + 0.002 in.
Doped silica (glass)High temperature polymide compoundTeflon FEP
Braided teflon coated fiberglassTeflon FEP
44
APPENDIX B: PRE-HVIAND POST-HVIAVIONIC LINE FUNCTIONALCHECKOUTDESCRIPTION
ThesecheckoutswereconductedbeforeeachHVI testandthenhandcarriedto theHIRL. After theHVI testwascompleted,thetestarticleswerereturnedto theEPSlab andthesecheckoutswererepeated.Thisallowedthecurrentcarrying"health"of thelinesto bedetemained.
Thefunctionalchecksfor thepower,1553databus,andcoaxiallineswereperformedattheEPSLaboratoryin building16atJSC. Thetestequipmentusedfor thispartof theprogramareasfollows:
1)
2)
3)
4)
5)
Slaughter Series 103/105 Dielectric Breakdown and Leakage Tester
Hewlett-Packard Model 3456A Digital Multimeter
Valhalla Scientific 2555A AC-DC Current Calibrator
Valhalla Scientific 4300B Digital Micro-ohmmeter
Fluke 343A DC Voltage Calibrator
The functional checks for the fiber optic lines were performed at the Fiber Optic TestBench in building 15 at JSC. The test equipment used for this part of the program are asfollows:
1) Noyes Optical Light Source OLS 1-2
2) Noyes Optical Power Meter OPM1-2
PRIMARY POWER LINE CHECKOUT
Resistance Test: Each test article was connected as shown in figure B 1. The insulation on atest article was fitted against the test blocks and the four bolts were torqued down to 134inch pounds (this provided a good tight contact without crushing the wires). The Fluke343A DC Voltage Calibration Source was set to 1 volt and the Valhalla 4300B micro-ohmmeter was set to test at 2 volts at 10 A. The resistance was then recorded from theValhalla 4300B.
SECONDARY POWER LINE CHECKOUT
Resistance Test: Each conductor of the test article was connected as shown in figure B2.The Valhalla 4300B micro-ohmmeter was set to 200 millivolts and 10 A (with notemperature compensation being used). The test was initiated and after one minute, thereading was recorded. This time allowed the test article to settle after experiencing anyinitial minor transient or heating effects.
Dielectric Breakdown Test: The Slaughter 103/105 Dielectric Breakdown and LeakageTester was set to the DC position, the voltage regulator to the X1 position and a 1200 voltsvoltage limit, and the current meter to the X1 position and a 100 gA limit. The timer was set
45
for 30seconds.Theconductorundertestwasthenconnectedto thepositivesideof thetesterwhileall remainingconductorsin thetestarticlebundlewereconnectedto thereturnside. ThepowerwasturnedonandtheSlaughter103/105wassetto automode.Thetestwasinitiatedandanycurrentleakagemeasuredon thecurrentmeterwasrecorded.If thearc indicatorlight namedon,thissignifiedthatthetesterdetectedacurrentleakageof greaterthan5 mA. Forthepurposesof thisphaseof thetestprogram,thiscurrentleakageconstitutedafailureof theline. This testwasperformedfor eachconductorof thetestarticle.
1553 DATA BUS LINE CHECKOUT
Resistance Test of Inner Conductors: This test is identical to the resistance test for the
secondary power lines except that the Valhalla 4300B micro-ohmmeter was set to 1 A.
Resistance Test of Shield: This test is identical to the resistance test for the secondarypower lines except that the Valhalla 4300B micro-ohmmeter was set to 20 millivolts and 1A.
Dielectric Breakdown Test: This test is identical to the dielectric breakdown test for the
secondary power lines except the voltage regulator was set to a 1000 volts voltage limit.
COAXIAL LINE CHECKOUT
Resistance Test of Inner Conductors: This test is identical to the resistance test for the
secondary power lines except that the Valhalla 4300B micro-ohmmeter was set to 20millivolts and 1 A.
Resistance Test of Shield: This test is identical to the resistance test for the secondarypower lines.
Dielectric Breakdown Test: This test is identical to the dielectric breakdown test for the
secondary power lines except the voltage regulator was set to a 1400 volts voltage limit.
FIBER OPTIC LINE CHECKOUT
Light Transmission Degradation Test: Before each fiber optic line was checked, a specificprocedure was performed as shown in figure B3. The Noyes Optical Power Source andOptical Light Meter were set for a wavelength of 1.3ktm. A launch cable was attached and a
reading taken, reading X. The launch cable is a special fiber optic line with a calibratedattenuation and is used to establish a baseline loss measurement for the checkouts that will
be performed. Because the light source and meter could not be physically connected toobtain this measurement, the launch cable was required.
Next, a reading was taken for each fiber optic line test article, reading Y, using theconfiguration shown in figure B4. The launch cable is required here to insure that thebaseline loss measurement, established above, is maintained. Finally, reading Y issubtracted from reading X to obtain the losses for the fiber optic line test article.
46
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XdB [
Optical LightSourceOLS1-2
Optical PowerMeter
OPM1-2
Figure B3. Setup for Establishment of Fiber Optic Cable Baseline Conditions
Launch CableMating Adaptor
UDS F/O Cable
Optical LightSourceOLS1-2
Optical PowerMeter
OPM1-2
Figure B4. Setup for Determining Losses in Fiber Optic Cable
49
APPENDIX C: LIST OF NASA PHOTOGRAPHS FROM TEST PROGRAM
HIRL Shot No, Photo NO,
1940 S92-27131 - $92-271361941 S92-27392 - $92-27396A 1492 $92-27125 - $92-27130A1493 S92-27178 - S92-27184A1494 $92-27397 - S92-27399A1498 $92-28248 - $92-28251A1500 $92-27914- S92-27917A1505 $92-28274- $92-28277A 1507 $92-28311 - $92-28313A1509 $92-29010- $92-29013A1517 S92-29006- $92-29009A1526 S92-29724 - $92-29728A1532 $92-31113 - $92-311172020 S92-32079 - $92-32082A1539 $92-32519 - $92-32521A1543 $92-32758 - $92-32759A1576 $92-36091 - $92-36094A1578 $92-36095 - $92-36098
A1613A1614A1622A1626A1631A1640A1651A1688A1690A1693A1695A1749A1750A1751
Photo No,
S92-39034- $92-39036S92-39037- $92-39040
N/A$92-41718-$92-41721$92-41715- $92-41717,$92-41722
N/AS92-43375- $92-43380S92-47372S92-47371S92-47368S92-47370$92-49389$92-49381$92-49385
&$92-47375& $92-47374
& $92-47369& $92-47373-$92-49392-$92-49384-$92-49388
50
APPENDIX D: BUMPER-E VULNERABILITY ANALYSIS OF THE UDS TRAYS
//
.EnBineer.;n_ & Sciences Company
ENGINEERING AND SCIENCE PROGRAM2400 Nt-,SARoad 1, P.O. t,ox 58561, HOuston,Texas 77258-8561713-333-5"11
March 30, 1992M.DS-505
TO" ScottLazaroff/NA SA- J SCjEP53
Via: Eric Christian serd'NAS A- J SC/S N 3Robert Franson,n_.ES C/B22 _ 9"Demos Ts_s/LESC_JB22 ,..07-
FTOm: James L. Hyde/LES CUB22Gfilian L. Shephazd/tESC/B30
Subject: PREDICTED NL.,nVIBER OF METEOROID AND DEBRIS IMPACTS ONTHE UTILITY DISTRIBUTION SYSTEM (UDS) TRAY
Please find attached the preliminary results of oar BUMPER-E vulnerability analysis of the UDSways. The predictions are based on a finite element model (I=EM) of the full ITDS way in the PMCconfimn'_don (]..VL/-I attitude). The FEM was developed from a desi=masketch tided "PIT UTILITYCARRIERS -- FLAT PATTERN." Table 1 lists the tray dimensions that were shown in the sketch.Table 2 _ves probability of no impact (PARDand expired number of impacts on the avionics andfluids secdons for seven test panicle diameters. The "energy, scmJed_ameters" shown in the secondand third columns of _zble 2 were ca]cuJam,d using the equations 1 and 2.
Meteoroids: d.,=d=, _-_j x (Eq. 1)
Where p = 05 glee for 3/8", ]/4" & 1/8" particles and 1.0 glee for others...
x( 7 y'Debris: d,_ = d,,.,, [, 10 ,) ('Sq. 2)
The results of thSsanalysisshould be classified as preliminary,. Additional runsshould be made attypical SSF atdmdes and a 6.rne-average prediction made for the expected number of impacts. TheBUMPER Phq code does not predict number of failures. It should be noted that one impact eventcould cause muldple failures in the utility _ray. A more refined analysis will be performed in thefuture.
°
Ja_es L. HydeStructures and Mechanics Deparmaent
Gill.JanL. ShephardStructures and Mechanics Deparmaent
51
Table D 1. UDS Tray Dimensions
tray
segment$3
$2
$1
M1
P1
regionB1
B2
B1
B2
B3
B4
B1B2
B3B4
B5
B6B1
B2
!length (in) avionics97.110 12.0
104.470 21.0
91.950 21.0
80.430 21.0
53.310 21--_33
54.310 33.0
101.200 33.0
100.420 33.0
101.380 33.0
68.235 33.0
68.235 33.0
100.530 33.0
98.530 33.0
96.530 33.0
compartment width (in)
face 2 (upper)
compartment width (in)
face6 (lower)fluids total avionics fluids total
0.0 12.0 12.0 0.0 12.0
3.7 24.7 20.0 3.7 23.7
9.0 30.0 20.0 9--> 11.5
9.0 30.0 17.5 11.5 29.0
9.0 17.5--_33i 11.5 -
9.0 42.0 33.0 11.5 44.5
9.0 42.0 33.0 11.5 44.5
9.0 42.0 33.0 11.5 44.5
9.0 42.0 33.0 11.5 44.59.0 42.0 33.0 11.5---> 14 -
9--->11.5 - 33.0 14.0 47.0
11.5 44.5 33.0 14.0 47.0
11.5 44.5 33.0 14.0 47.011.5 44.5 33.0 14.0 47.0
P2
P3
B4 96.530 33.0
B5 98.530 33.0
B1 100.530 33.0
B2 68.235 33.0
B3 68.235 33.0
B4 101.380 33.0
B5 100.420 33.0
B6 101.200 33.0
B1 54.310 33.0
B2 53.310 33--->15
B3 80.430 15.0
B4 91.950 15.0
B 1 104.470 15.0
B2 97.110 12.0
11.5 44.5 33.0 14.0 47.0
11.5-->9 - 33.0 14.0 47.0
9.0 42.0 33.0 14.0 47.0
9.0 42.0 33.0 14.0 47.0
9.0 42.0 33.0 14-->9
9.0 42.0 33.0 9.0 42.0
9.0 42.0 33.0 9.0 42.0
9.0 42.0 33.0 9.0 42.0
9.0 42.0 33.0 9.0 42.0
9.0 33--->15 9.0
9.0 24.0 15.0 9.0 24.0
9.0 24.0 15.0 9.0 24.0
3.7 18.7 15.0 3.7 18.7
0.0 12.0 12.0 0.0 12.0
52
.,<0
c_
..0
ILl 14,1
0_1 COl _'-I 0
. :"o _' _' r..,:"r,.: "o c_ ml °'1 c_l _""" _ "s " _ ,'-_ _ "_ '__1_1'_1_ -_ ° oo
c; _d co m o_I-- x
o
= 1 _ o'_'o'_'_ _ i_ °°_o" o" c:;" c; orr ,,:[
53
REPORT DOCU M ENTATION PAGE Form ApprovedOMaNo.ozo_o,sa
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1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED
July 1993 Technical Memorandum
4. TITLE AND SUBTITLE 5. FUNDING NUMBERS
Hypervelocity Impact Testing of the Space Station Utility
Distribution System Carrier
6. AUTHOR(S)
Scott Lazaroff, Johnson Space Center
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)
Propulsion and Power Division
Lyndon B. Johnson Space Center
Houston, Texas 77058
9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES)
National Aeronautics and Space Administration
Washington, D.C. 20546
8. PERFORMING ORGANIZATIONREPORT NUMBER
S-723
10 SPONSORING/MONITORINGAGENCY REPORT NUMBER
NASA-TM-104771
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12a. DISTRIBUTION/AVAILABILITYSTATEMENT
National Technical Information Service
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(703) 487-4600Unclassified/Unlimited Subject Category 20
13. ABSTRACT (Maximum 200 words)
12b. DISTRIBUTION CODE
A two-phase joint NASA Johnson Space Center and McDonnell Douglas Aerospace-HuntingtonBeach hypervelocity impact (HVI) test program was initiated to develop an improved
understanding of how meteoroid and orbital debris (M/OD) impacts affect the Space
Station Freedom (SSF) avionic and fluid lines routed in the Utility Distribution System
(UDS) carrier. This report documents the first phase of the test program which covers
nonpowered avionic line segment and pressurized fluid line segment HVI testing. Fromthese tests, a better estimation of avionic line failures is approximately 15 failures
per year and could very well drop to around 1 or 2 avionic line failures per year
(depending upon the results of the second phase testing of the powered avionic line at
White Sands). For the fluid lines, the initial McDonnell Douglas analysis calculated 1
to 2 line failures over a 30 year period. The data obtained from these tests indicate
the number of predicted fluid line failures increased slightly to as many as 3 in the
first 10 years and up to 15 for the entire 30 year life of SSF.
14. SUBJECT TERMS
Hypervelocity Impact, Meteoritic Damage, Space Debris (Damage),
Impact Damage, Impact Tests,
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Unclassified
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